The principles of bidding are openness, fairness and justice. Only fairness and openness can attract truly interested and competitive bidders to compete. Bidding documents should specify supporting bid evaluation factors or methods, and try to be as scientific and reasonable as possible. This will make the bidding activities more open, reduce human factors, and make potential bidders more interested. It should also be noted that the specifications of the bidding documents must not require or indicate a specific patent, trademark, name, design, model, place of origin or manufacturer, and must not tend to or exclude a legal person or other person interested in bidding. Organizational content. 5. Scientific and standardized Use the most standardized words to describe the purpose, requirements, progress, after-sales service, etc. of the procurement in a concise, orderly, accurate and clear manner. The words and expressions in the bidding documents must be accurate and clearly expressed. Uncertain statements such as approximate and approximate, as well as ambiguous statements are not allowed. Use as few or no adjectives as possible. It is prohibited to use ambiguous language to prevent The bidder has a misunderstanding. A bidding document must achieve five unifications, namely unified format, unified fonts, unified language, unified use of numbers, and unified use of technical requirements. 6. Protect the interests of the government, schools, and enterprises. When preparing bidding documents, attention should be paid to maintaining the confidentiality of the user unit. For example, when purchasing network equipment in colleges and universities, security issues must be considered. It must not harm national interests and public interests. For example, noise pollution must meet standards. 2. Several important links in the preparation of bidding documents 1. The preliminary demonstration work should be sufficient. The demonstration mainly solves three aspects of the problem. The first is to avoid blindness in purchasing equipment and overcome shortcomings such as repeated purchases and low utilization. Second, coordinate equipment investment planning and optimize resource allocation. Third, through demonstration, fully tap the use potential of precision equipment and promote the sharing of resources and dedicated management and use.